Travelling hydraulic development frame for mining operations



Dec. 28, 1965 E. HOFFMANN 3,225,547

TRAVELLING HYDRAULIC DEVELOPMENT FRAME FOR MINING OPERATIONS Filed Sept. 1. 1964 2 Sheets-Sheet 1 IN VE N TOR ZIP/CH HOFF/M/V/I BY Dec. 28, 1965 E. HOFFMANN 3,225,547

TRAVELLING HYDRAULIC DEVELOPMENT FRAME FOR MINING OPERATIONS Filed Sept. 1. 1964 2 Sheets-Sheet 2 g I 36b 25 29 29g 390 Q 3s 39 26 IN VE N TOR flTTOF/YEYY United States Patent- 3,225,547 TRAVELLING HYDRAULIC DEVELOPMENT FRAME FOR MINING OPERATIONS Erich Hoffmann, Altluenen, Westphalia, Germany, assignor to Gewerkschaft Eisenhuette Westfalia, Westphalia, Germany, a corporation of Germany Filed Sept. 1, 1964, Ser. No. 393,662 Claims priority, application Germany, Apr. 27, 1960, G 29,546 Claims. (Cl. 61-45) This invention relates to a movable frame for use in mining and is a continuation-in-part of application Serial No. 86,136 filed January 31, 1961, now Patent No. 3,174,- 289 as to the sole invention of the instant inventor disclosed therein.

The type of frame to which this invention relates more particularly includes an arrangement of movable pit props which move along progressively on rails and support the roof of the working.

Commonly, such frames shift ahead through pneumatically or hydraulically operated cylinders with pistons. The two frames are alternately displaced parallel to each other. They consist of two frames connected with one another through guides. The moving ahead of the individual frames takes place by swinging one frame around the stationary other frame.

The disadvantage of the known development frames is, above all, in the lack of adaptability to the conditions given. They may 'be shifted only in straight line in the longitudinal direction of the overhead and bottom rail. However, frequently a lateral shift, even though only slight, is desirable and even necessary. One need only think of the occurrence of a disturbance in the underground mining installation, of loosened rock layers or of a change of the overhead conditions, through which is made necessary or desirable a change of the distance of the operations and frames from one another. For example, it may be possible at the start of the removal of a prop that the roof was comparatively good, so that the individual frames could be positioned at comparatively large intervals from one another along the coal deposit. As the work progresses, the roof may then become worse, so that it is necessary to position the development frames closer. This means that the development frames must be shifted more closely together, namely in the direction about parallel to the coal deposit, or that, with the spacing of the props remaining the same, additional development frames must be brought in. This mentioned parallel displacement to the coal deposit is difficult or impossible with the customary development frames. 7

The invention has as its object to create a development frame which may advance in the direction to the coal eposit under simultaneous lateral displacement, thus taking place parallel to the coal deposit. For this, the inventor proposes that two racks of the frame be connected together with a shifting devic to permit the change of the interval between both racks and a certain angular position with respect to one another. The means effecting these changes may be at both ends of the frame.

The change of distance between both racks of a frame and the mentioned angular position may be obtained. by connecting each end of the racks by a link, whose effective length is variable, with the shifting device. For this purpose the connection of the racks to each other and to the shifting device may take place via hydraulic cylinders, acting substantially transversely to the plane of the rack which, as the case may be, act on the aforementioned link. An efficient arrangement provides at one end of the frame one rack connected with the shifting device and at the other end of the frame the other rack connected with the shifting device, in each case via a hydraulic cylinder.

3,225,547 Patented Dec. 28, 1955 In the drawing are shown two examples of execution of the invention wherein FIG. 1 is a plan view of an embodiment of an hydraulically operated development frame; and

FIG. 2 is a plan view of an alternate embodiment of the development frame.

Referring to the drawing, and particularly to FIG. 1, the development frame consists of two racks 10 and 11. Each of these two racks has in each case horizontal skids 12 and 13, two pit props 14 and 15 for skid 12 and two pit props 16 and 17 for skid 13. Props 14, 15, 16, and 17 are hydraulically operated and are extensible columns which extend upwardly from the floor to the roof where they bear against suitable heads or rails to support the roof. The details of the props and the rails are omitted for the sake of simplicity, as they are not part of the present invention. Interposed between the skids or racks 12 and 13 is a piston cylinder means including the cylinder 22 and the piston rod 23. The piston cylinder means may be of the usual type in which a piston disc (not shown) is mounted fixedly on the piston rod 23 such that the double acting cylinder 22 slidably encloses the same with the ends of piston rod 23 extending through the ends of the cylinder 22. Thus, hydraulic or pneumatic fluid, or the like, will enter and leave the double acting cylinder 22 through the ports 22a whereby when pressure fluid enters through one of the ports it will force the cylinder away from the piston disc (not shown) and cause in turn pressure fluid within the cylinder on the other side of the piston disc to exit through the remaining port 22a. The cylinder is double acting in that the same will move in both directions alternately, depending upon which port 22a is used to introduce pressure fluid and which is used to exhaust pressure fluid from the cylinder. The piston rod 23 is articulatcdly connected at its ends to the fixed length transverse arm 18, and the variable length transverse arm 19, such that at the widened portions 23a a certain amount of play will be permitted between the ends of rod 23 and the arms 18 and 19. On the other hand, cylinder 22 is connected fixedly by means of the straps 24a to the elongated interconnection element 24 which in turn is connected by the variable length arm 20 and the fixed length arm 21 to the skid or rack 13. While arm 21 is articulatedly connected at 21a with one end of elongated element 24 and arm 20 is fixedly connected with the other end of elongated element 24, it will be appreciated that both of these connections as well as the connections between the ends of rod 23 and the arms 13 and 19 may be fixed or articulated connections, as desired, inasmuch as where articulated connections are used, the corresponding parts can be made of relatively nondeformable material whereas when fixed connections are used, the parts in question may be made from relatively deformable material, such as resilient straps.

The need for articulated connections or for fixed connections of relatively resilient interconnected parts will become apparent with regard to the concept of the variable length arms 19 and 20. In the case of arm 19, a guide 19a is provided, which is formed by two U-shaped strips 1% and 19c which are turned toward one another at their open ends so as to form one member into which the remainder of arm 19 is telescopingly received. The range of telescoping movement approximately corresponds to the length of the strips 19b and 190. The connection between the member represented by the parts 1% and 190, on the one hand, and the remainder of arm 19, on the other hand, is carried out by means of the transverse cylinder 19d connected to the outer end of arm 19 and the piston rod 19f connected at one end to the base on rack 12 carrying the U-shaped strips 1% and 190, with the free end of the transverse piston rod 19f carrying the transverse piston 19e operatively disposed within the transverse cylinder 19d. By suitably energizing the transverse cylinder arrangement, the arm 19 may be moved in a particular transverse direction to increase or decrease the amount of telescoping engagement with the member composed of the strips 19b and 190.

In the same way, with respect to the variable length arm 20,- a similar guide 20a is provided having the U- shaped strips 20b and 200 turned toward one another with their open ends so as to form a member into which the outer end of arm 20 telescopingly is received. The transverse cylinder 20a. is mounted at the end of arm 20 adjacent the rack 13 while the piston rod 20 carrying the piston 20e at its free end operatively within the cylinder 20a is connected at its outer end to the base 16a of rack 13. Depending upon the direction of energizing the piston cylinder means, the outer end of arm 20 will increase or decrease the amount of telescoping engagement with the member composed of the strips 201) and 200.

Accordingly, due to the presence of the longitudinal moving means in the form of the piston rod 23 operatively received within the cylinder 22, as the cylinder is energized in one direction, the piston rod 23 and the cylinder 22 will be displaced longitudinally with respect to one another. Assuming that the pit props or mining props 14 and 15 are extended into engagement with the mine ceiling to hold rack 12 stationary, while the pit props 16 and 17 are retracted from engagement with the mine roof so as to render rack 13 displaceable, then by introducing pressure fluid, such as hydraulic fluid or pneumatic fluid, into the uppermost port 22a of cylinder 22 as seen in FIG. 1, such pressure fiuid will work against the piston disc (not shown) on rod 23 forcing the cylinder 22 to ride along rod 23 in a forward direction toward arm 18. As this is done, due to the connecting straps 24a and the elongated element 24 which is attached at its ends to arms and 21, the rack 13 will be displaced in a corresponding forward direction as well. Then the pit props 16 and 17 can be extended into engagement with the mine roof and the pit props 14 and 15 disengaged from the mine roof by retracting the same. When this has been done, the reverse procedure may be carried out, i.e. pressure fluid may be introduced through the lowermost port 22a of cylinder 22 so as to cause the piston disc (not shown) and in turn rod 23 and rack 12 connected thereto by arms 18 and 19 to be displaced in the forward direction of movement or travel. By alternately repeating this procedure, racks 12 and 13 may be longitudinally displaced with respect to one another depending upon whether the pit props 14 and 15, on the one hand, or the pit props 16 and 17, on the other hand, are placed into engagement with the mine roof, with the remaining pit props being in retracted position to permit the displacement to be carried out.

Nevertheless, it is desirable that the racks 12 and 13 be able to advance not only in the normal longitudinal direction but also in an angular direction with respect to the longitudinal as where it is desired to rearrange the racks and pit props laterally as well as longitudinally within the working space at the mineway. In accordance with the present invention, by changing the length of the variable length arm 19 or that of the variable length arm 20, or both, it will be realized that the racks 12 and 13 may change their angular disposition with respect to the longitudinal and with respect to one another, whereby upon actuation of the cylinder 22 and piston rod 23 lateral and/or angular movements of the particular rack will take place along with the longitudinal movement thereof.

For example, by increasing the telescoping engagement with respect to the arm 19 so as to shorten the effective length thereof, in the case where the pit props 14 and 15 are in engagement with the mine roof and the pit props 16 and 17 retracted from such engagement, the rack 12 will remain in the original longitudinal position as shown in FIG. 1 whereas the rack 13 as Well as the piston rod 23 will assume a slanting direction toward the upper right as viewed in FIG. 1. When the piston cylinder means comprising cylinder 22 and piston rod 23 is next energized, rack 13 will move upwardly and outwardly along the angle line outwardly diverging toward the upper right as viewed in FIG. 1. Analogously, by decreasing the effective length of the arm 20, similar angular movements may be effected. Of course, by increasing the effective length of either arm 19 or 20, or both, other changes in the direction of movement can be effected.

The articulated connections between the ends of the rod 23 and the arms 18 and 19 at 23a permit arm 19 to change its effective length without stress on the interconnected parts. The same is true with regard to the elongated element 24 which is articulatedly connected at 21a with the fixed length arm 21. Of course, the connection between arm20 and element 24 may be an articulated connection if desired, or no articulated connections may be used, but instead the arms 18 and 19, on the one hand, and 20 and 21, on the other hand, may be made of comparatively resilient material, at least along a portion thereof, and/or the piston rod 23 and the elongated element 24 may be made of such comparatively resilient material. The same is true for the skids or racks 12 and 13, whereby not only unevenness in the mine floor may be effectively accommodated but also changes in the angular position of the piston cylinder means, including cylinder 22 and piston rod 23 with respect to one or both of the racks 12 and 13.

The piston cylinder means including cylinder 22 and piston rod 23 may be oval, rectangular, or circular in cross-section, as desired, and the longitudinal cylinder 22 and/or the elongated element 24 may be constructed so as to normally rest against the ground. Where the cylinder 22 and the piston rod 23 as well as the piston disc (not shown) are circular in cross-section or otherwise permitted to rotate about their common axis as where the piston disc is free to rotate yet is fixed from longitudinal movement along piston rod 23, rack 12 may be transposed onto rack 13 about the axis of rod 23 to provide a compact frame device arrangement capable of storage in a minimum of space. To this end, the pit props or mining props 14, 15, 16, and 17, will be advantageously retracted into their shortest length to enhance the compactness of the storable unit, although the pit props are usually removable whereby the frame device may be stored in the aforementioned compact disposition without the pit props attached thereto.

The development frame of FIG. 2 of the drawing likewise consists of two racks 25 and 26. Each of these racks indicates where two props are mountable in prop shoes 27, which are connected with one another by skids 28. At the prop shoes 27 are mounted arms 29 and 30, between whose ends are braced the piston rods 31 and 32, rod 31 being on the left-hand arms 29 and 30, and rod 32 being on the right-hand arms 30 and 29. The two frames 25 and 26 are connected with one another via a cylinder block 33, which consists of two parallel cylinders 34 and 35, longitudinally spaced apart. To the cylinders 34 and 35 are assigned the two piston rods 31 and 32, respectively. The alternately shifting ahead of the two racks occurs via these two cylinders 34 and 35.

In order to bring about a change of direction in which the two racks 25 and 26 are pushed ahead through the cylinders 34 and 35, the cylinders 34 and 35 and the piston rods 31 and 32 may be brought into a position diverging from the parallel course to the two racks 25 and 26. Such a change in direction is effected in such a manner that the arms 30 of both racks 25 and 26 are lengthened or shortened in the same way as in the case of the embodiment of FIG. 1. The arrangement is such that the arms 30 engage in each case into a guide 36, which is formed by two U-shaped strips 36a and 36b. The two U-shaped strips 36a and 36b are turned toward one another with their open ends. As the drawing of FIG. 2 shows, the two arms 30 may telescope somewhat, which approximately corresponds to the length of these strips 36a and 36b. The connection between both parts, namely the slides or arms 30 and the parts 27a and 27b, respectively of the prop base having openings 27 for receiving the pit props (not shown), takes place via hydraulic cylinders 37 which are mounted transversely at the arms 30. The transverse pistons 38 coact with these transverse cylinders 37 via piston rods 39, mounted transversely on parts 27a and 27b, respectively of skids 28. The arrangement may also be so constructed that the point of fastening of the piston rods 31 and 32 at the arms 34 is variable, and that the fastening of the arms 30 at the said piston rods takes place via a hydraulic cylinder, and the same is true with respect to the arrangement of FIG. 1. The two racks and 26 and the development frame formed by them are in practice placed essentially perpendicular to the course of the coal deposit, that is to say, that one of the two cylinders 37 is situated at the coal deposit side and the other of the two cylinders is situated away from the coal deposit at the gobbing side. The shifting takes place in both racks 25 and 26 by the same procedure as above described, so that the piston rods remain parallel to one another also after operation of the cylinders 37. If, for example, the development frame is to be shifted somewhat toward the left in the view of FIG. 2 of the drawing, it would be necessary to pull, via the cylinder 37 at rack 25, the arm into part 27a of the prop shoe 27. A corresponding movement would also take place at arm 30 of the rack 26. Here arm 30 is pulled into part 27b of pro shoe 27, the two piston rods 31 and 32, respectively thereby obtaining a slanting position with respect to the two racks 25 and 26. That is to say, they have been shifted below, toward the left, and above toward the right, as seen in FIG. 2. If now, the two cylinders 34 and 35, or either one of them individually, would be operated, then the development frame would be moved ahead in the direction which is determined through the new position of the piston rods 31 and 32 and of the cylinders 34 and 35. \Vhen a sufficient lateral displacement has been reached, the piston rods may again be adjusted parallel to the two racks 25 and 26, that is to say, the piston rods with the cylinders again come into their position perpendicular to the coal deposit.

Of course, that means that also arms 29 are movable with respect to the prop shoes 27 to which they are attached or pivotably mounted at least within certain limits, in order to take part in the tilting of piston rods 31 and 32 with respect to racks 25 and 26, instead of being rigid.

On the other hand, the arrangement may also be thus constructed that the piston rods 31 and 32 are mounted with their ends in such a way that the arms 29 and 30, that they, namely the piston rods, can be pivoted to a certain extent against the arms 29 and 36. This, for example, may only be effected in such a manner, as indicated at 29a and 30a, that the ends of the piston rods are gripped by the ends of the arms 29 and 30 under provision of a free space.

Thus, with respect to both embodiments of FIGS. 1 and 2, the travelling hydraulic development frame may be moved alternately in a longitudinal direction as well as angularly to accomplish a lateral displacement along with the longitudinal displacement. After releasing the two props on the right hand rack from engagement with the roof, for instance, yet keeping the props on the left-hand rack in engagement with the mine roof, and decreasing the length of the particular variable length arm means connected to the left-hand rack, such that the linear direction of movement of the longitudinal moving means will be at an angle upwardly and outwardly diverging from the left-hand rack, the moving means may be energized to displace the right-hand rack both forwardly and outwardly with respect to the original longitudinal position of the left-hand rack. This movement will take place regardless of the length of the arm connecting the right-hand rack with the moving means. On the other hand, when the particular advance has been completed, the props on the right-hand rack will be extended into engagement with the mine roof and the props on the lefthand rack will be retracted from such engagement. Then the moving means may be energized once more and the left-hand rack will move forwardly in the linear direction of movement of the moving means at that point. Of course, before each advance of a particular rack, one or both of the variable length arm means may be changed in its effective length so as to displace angularly the moving means with respect to a particular rack and perhaps also the other rack with respect thereto.

The opposite effect may be realized by increasing the length of the particular variable length arm means connecting the moving means with the left-hand rack and/ or also the effective length of the variable length arm means connecting the right-hand rack with the moving means. Once more assuming that the pit props on the left-hand rack are in engagement with the mine roof while the pit props on the right-hand rack are released from such engagement, the right-hand rack will move forwardly and to the left because of the new angular disposition of the linear path of movement of the moving means.

Accordingly, so long as the linear direction of movement of the moving means is at an angle to a particular rack which is stationarily positioned, th corresponding rack will be moved linearly in the direction of movement of the moving means whether such rack being moved is parallel or at an angle with respect to the new linear direction of movement of the moving means. Before each advance, the angular disposition of the moving means with respect to the longitudinal direction of the particular rack which is maintained stationary may be changed by changing the effective length of the corresponding variable length arm means in order to control the direction of movement longitudinally forwardly, or both longitudinally forwardly and angularly or laterally. It will be realized that in accordance with the embodiment of FIG. 2 one rack may be rotated about the axis of one or both of the piston rods, respectively, so as to overlie the remaining rack in order to form a compact unit in the same manner as noted above in connection with the embodiment of FIG. 1.

Accordingly, the present invention relates to an advancing rack assembly for a mining prop arrangement, which comprises a pair of racks arranged in side by side relation, longitudinally operative moving means interposed betwen the racks, and connecting means interconnecting the racks with the moving means including variable length arm means for adjusting angularly at least one said rack with respect to the other, the moving means through the connecting means operating to displace longitudinally the racks with respect to one another and in dependence upon the length of the variable length arm means to displace angularly said at least one rack with respect to the other as well.

More specifically, the advancing rack assembly may comprise a first longitudinal rack and a second longitudinal rack in side by side relation, adapted for supporting thereon mining prop overhead bearing means which alternately extend into and retract from engagement with a mine roof, longitudinally extending coacting moving means including a first moving part and a second moving part disposed between the racks, the parts being operatively interconnected for alternate movement longitudinally with respect to one another, yet being secured from transverse and angular movement with respect to one another, a first arm of substantially fixed length interconnecting transversely the first rack with the first part and a second arm of substantially fixed length interconnecting transversely the second rack with the second part, first variable length connecting means spaced longitudinally from the first arm and interconnecting transversely the first rack with the first part and second variable length connecting means spaced longitudinally from the second arm and interconnecting transversely the second rack with the second part, at least one of said first arm and said first variable length connecting means interconnecting articulatedly said first part and at least one of said second arm and said second variable length connecting means interconnectig articulatedly said second rack with said second part, and means to vary the length of the connecting means.

Specifically, the first and second arm means may be disposed at opposite longitudinal ends of the racks, and the first and second variable lengths connecting means in turn may be disposed at correspondingly opposite longitudinal ends of such racks.

In this way, a construction may be provided where the first and second variable length connecting means are articulatedly connected at one end to the corresponding moving part and substantially fixedly connected at the opposite end to the corresponding rack, and the first and second arms are articulatedly connected at one end to the corresponding moving part and substantially fixedly connected at the opposite end to the corresponding rack, where the means to vary the length of the variable length connecting means includes a corresponding coacting transverse piston cylinder means extending operatively in the direction of each said variable length connecting means, and where each variable length connecting means includes a pair of telescoping members, one such member being connected substantially fixedly to the corresponding rack and the other such member being connected articulatedly to the corresponding moving part, the transverse piston of such transverse piston cylinder means being connected to one of the telescoping members, and the transverse cylinder of the transverse piston cylinder means being connected to the other of the telescoping members, whereby upon coaction of a particular transverse piston cylinder means the length of the corresponding variable length connecting means will vary and in turn the corresponding rack and moving part interconnected thereby will diverge with respect to one another and define an angular position with respect to one another difiering from their previous position with respect to one another. Specifically, in accordance with such construction, the moving means may include coacting longitudinal piston cylinder means having a pair of parallel piston rods as the moving parts, each such rod carrying a corresponding double acting piston disc fixedly thereon remote from the ends thereof, and a corresponding pair of parallel double acting cylinders operatively slidably enclosing the corresponding pistons and each having a corresponding forward head end and a rearward head end slidably mounted on the rods, said cylinders being fixed with respect to one another against longitudinal and transverse displacement and being longitudinally offset with respect to one another such that the forward head end of one such cylinder is adjacent the rearward head end of the other such cylinder while the rearward head end of said one such cylinder is remote from the forward head end of said other such cylinder, the ends of the rods extending outwardly beyond the corresponding ends of the cylinders, and the racks being interconnected by said arms and said variable length connecting means to the corresponding ends of the rods, respectively.

In accordance with a further construction, the moving means include coacting longitudinal piston cylinder means having as the moving parts a longitudinal piston rod carrying a double acting piston disc fixedly thereon remote from the ends thereof and a corresponding double acting longitudinal cylinder operatively slidably encIosing the piston and slidably mounted on the rod, the ends of the rod extending outwardly beyond the corresponding ends of the cylinder, wth a longitudinally extending elongated element being provided between the cylinder and one of the racks and fixedly secured to the ends of the cylinder, and with the first arm being articulatedly connected at one end to one end of the rod and substantially fixedly connected at the opposite end to a particular rack, the first variable length connecting means being articulatedly connected at one end to the opposite end of such rod and substantially fixedly connected at the opposite end to the particular rack. Moreover, the second arm in this construction is analogously articulatedly connected at one end to one end of the elongated element and substantially fixedly connected at the opposite end to the remaining corresponding rack while the second variable length connecting means is substantially fixedly connected at one end to the opposite end of the elongated element and substantially fixedly connected at the opposite end to the remaining corresponding rack. The means to vary the length of the variable length connecting means, in this regard, includes a corresponding coacting transverse piston cylinder means extending operatively in the direction of each such variable length connecting means, and each variable length connecting means includes a pair of telescoping members, one such member of each variable length connecting means being connected substantially fixedly to a corresponding rack with the other such member of one of the variable length connecting means being connected articulatedly to the piston rod, with the other said member of the other of the variable length connecting means being connected fixedly to the adjacent end of the elongated element. Analogously, the transverse piston of the transverse piston cylinder means is conneced to one of the telescoping members and the transverse cylinder of the transverse piston cylinder means is connected to the other of the telescoping members, whereby because of the foregoing construction, upon coaction of a particular transverse piston cylinder means, the length of the corresponding variable length connecting means will vary and in turn the corresponding rack and piston cylinder means moving part interconnected thereby will diverge with respect to one another and define an angular position with respect to one another differing from their previous position with respect to one another.

Generally, therefore, the travelling hydraulic frame device for mining of the present invention comprises a pair of prop-supporting racks arranged side by side, arms extending from the ends of each rack toward the arms of the other rack, longitudinally disposed piston rods in side by side relation and mounted on the arms, a pair of longitudinal cylinders integrally interconnected and containing the piston rods, and hydraulic cylinder and piston means to change the effective length of certain of the arms. Alternately, the travelling hydraulic frame device for mining in accordance with the invention comprises a pair of prop-supporting racks arranged side by side, arms extending from the ends of each rack toward the arms of the other rack, a longitudinally disposed piston rod mounted on the arms of one of the racks and a longitudinally disposed cylinder mounted on the arms of the other of the racks and operatively containing the piston rod, and hydraulic cylinder and piston means to change the effective length of certain of the arms.

It will be realized in accordance with the foregoing that while it may be desirable to decrease or increase the effective length of both of the variable length connecting means or arms to the same extent, whereby the longitudinal direction of movement of the moving means is at an angle with respect to the racks, it is actually only necessary that the moving means he at an angle with respect to the stationary rack whereby to execute a linear movement angularly toward or away from such stationary rack depending upon the direction of advance. The rack which is shifted with the corresponding part of the moving means will move in the desired angular direction regardless of whether such shifted rack is parallel to the stationary rack or parallel to the linear direction of movement of the moving means or at some other angular position. Of course, when the alternate shifting of the previously stationary rack is to take place,

then the previously shifted rack which becomes the stationary rack must be adjusted as desired through the variable length arm means or the like so that the linear operative direction of movement of the moving means with respect thereto will displace the previously stationary rack which is now to be shifted along the desired path and in the desired direction, either longitudinally or angularly as the case may be. Broadly speaking, while the racks may be maintained parallel to one another throughout or at an angle with respect to one another, the particular stationary rack will always be maintained at an angle with respect to the linear direction of movement of the moving means in order to effect angular or lateral displacement of one rack with respect to the other, as the artisan will appreciate.

As regards the embodiment of the invention, as shown in FIG. 2, the actual operation of the staggered or offset integrally connected cylinders is more fully described in copending US. application Serial No. 98,923, filed March 28, 1961, by the instant inventor. While the actual piston cylinder arrangement utilized in FIG. 2 herein is specifically disclosed and claimed in said copending application, the concept of variable length connecting arms of the instant type is disclosed and claimed herein, regardless of the particular moving means employed, as for ex ample the piston cylinder arrangement of FIG. 2 herein as aforesaid or the piston cylinder arrangement of FIG. 1 herein.

Other equivalent modifications of the present invention will occur to those skilled in the art, which are within the scope of the present invention as limited only by the appended claims.

What is claimed is:

1. Advancing rack assembly for a mining prop arrangement, which comprises a pair of racks arranged in side by side relation, longitudinally operative moving means interposed between said racks and including coacting elongated portion movable longitudinally with respect to one another yet being secured in their entirety from transverse and angular movement with respect to one another, and connecting means interconnecting said racks correspondingly with said moving means via corresponding elongated portions thereof, said connecting means including variable length arm means for adjusting angularly within predetermined angular limits at least one said rack with respect to the other and also including longitudinally spaced therefrom at least one articulated connection in said connecting means between a corresponding one of said elongated portions of said moving means and said at least one rack having said at least one variable length arm means, said moving means through said connecting means operating to displace longitudinally said racks with respect to one another and in dependence upon the length of said variable length arm means to displace angularly said at least one rack with respect to the other as well.

2. Advancing rack assembly for a mining prop arrangement, which comprises a pair of elongated racks arranged substantially longitudinally in side by side transversely spaced apart relation, longitudinally operative elongated moving means interposed between said racks and spaced transversely therefrom and including coacting elongated portions movable longitudinally with respect to one another yet being secured in their entirety from transverse and angular movement with respect to one another, connecting means extending from said racks to said moving means and operatively interconnecting said racks with corresponding elongated portions of said moving means, said connecting means including substantially transverse variable length arm means for adjusting angularly at least one said rack with respect to the other and also including longitudinally spaced therefrom at least one articulated connection in said connecting means between a corresponding one of said elongated portions of said moving means and said at least one rack having said at least one variable length arm means for actuation substantially in the plane of said said racks, said moving means through said connecting means alternately operating to displace said racks with respect to one another longitudinally and angularly in dependence upon the length of said variable length arm means.

3. Advancing rack assembly for a mining prop arrangement, which comprises a pair of elongated racks arranged substantially longitudinally in side by side transversely spaced apart relation in a plane substantially parallel with the ground, longitudinally operative elongated moving means interposed between said racks and spaced transversely therefrom and including coacting elongated portions movable longitudinally with respect to one another yet being secured in their entirety from transverse and angular movement with respect to one another, and connecting means extending from said racks to said moving means and operatively interconnecting said racks with said moving means, said connecting means including articulated connection means in said connecting means between said moving means and said racks positioned for articulation about an axis substantially perpendicular to the plane of said racks, as well as including substantially transverse variable length arm means for adjusting angularly each said rack with respect to the other, and a substantially transverse and substantially fixed length arm means for each said rack for maintaining in fixed spaced relation the correspondingly adjacent portions of the particular rack and said moving means, said variable length arm means and said fixed length arm means being spaced longitudinally with respect to one another,

4. Assembly according to claim 3 wherein one said rack is interconnected at one end thereof with one corresponding end of one of said elongated portions of said moving means through one said fixed length arm means and at the opposite end thereof with the correspondingly opposite end of said one of said elongated portions of said moving means through one said variable length arm means, and wherein the other said rack is interconnected at one end thereof, corresponding to said one end of said one rack, with one corresponding end of another of said elongated portions of said moving means through another said variable length arm means and at the opposite end thereof with the correspondingly opposite end of said another of said elongated portions of said moving means through another said fixed length arm means.

5. Advancing rack assembly for a mining prop arrangement, which comprises a pair of elongated racks arranged substantially longitudinally in side by side transversely spaced apart relation, longitudinally operative elongated moving means interposed between said racks and spaced transversely therefrom and including coacting elongated portions movable longitudinally with respect to one another yet being secured from transverse and angular movement with respect to one another, and connecting means extend-ing from said racks to said moving means and operatively interconnecting said racks with said moving means, said connecting means including articulated connection means in said connecting means between said moving means and said racks as well as substantially transverse variable length arm means for adjusting angularly each said rack with respect to the other and substantially transverse and substantially fixed length arm means for each said rack for maintaining in fixed spaced relation the correspondingly adjacent portions of the particular rack and said moving means, said variable length arm means and said fixed length arm means being spaced longitudinally with respect to one another, one said rack being interconnected at one end thereof with one corresponding end of one of said elongated portions of said moving means through one said fixed length arm means and at the opposite end thereof with the correspondingly opposite end of said one of said elongated portions of said moving means through one said variable length arm means, the other said track being interconnected at one end thereof, corresponding to said one end of said one rack, with the corresponding end of another of said elongated portions of said moving means through another said variable length arm means and at the opposite end thereof with the correspondingly opposite end of said another of said elongated portions of said moving means through another said fixed length arm means, and each said variable length arm means including first member and a second member in telescoping engagement with one another and a transversely operative moving means including a first moving part and a second moving par-t coactive with one another for linear displacement with respect to one another, said first moving part being secured to said first member and said second moving part being secured to said second member for changing in turn the linear disposition of said members with respect to one another and the angular disposition of one of said racks with respect to the other.

6. Assembly according to claim 5 wherein said transversely operative moving means includes as said first and second parts corresponding transverse piston cylinder means.

7. Assembly according to claim 6 wherein said longitudinally Operative moving means includes corresponding longitudinal piston cylinder means.

8. Assembly according to claim 7 wherein said longitudinally operative piston cylinder means includes a pair of parallel piston rods as said elongated portions of said longitudinally operative moving means, each such rod carrying a corresponding double acting piston thereon substantially intermediate the ends thereof, and a corresponding pair of parallel double acting cylinders slidably mounted on said rods and operatively enclosing the corresponding pistons, said cylinders being fixed with respect to one another against longitudinal and transverse displacement, the ends of said rods extending outwardly beyond the corresponding ends of said cylinders, and said racks being connected by said arm means to said elongated portions of said longitudinally operative moving means at the corresponding ends of said rods, respectively.

9. Assembly according to claim 8 wherein the corresponding arm means is connected articulatedly to the corresponding rod end.

10. Assembly according to claim 7 wherein said longitudinally operative piston cylinder means includes a piston rod carrying a double acting piston thereon substantially intermediate the ends thereof and a corresponding double acting cylinder slidably mounted on said rod and operatively enclosing said piston as said elongated portions of said longitudinally operative moving means, the ends of said rod extending outwardly beyond the corresponding ends of said cylinder, and said racks being connected by said arm means to said elongated portions of said longitudinally operative moving means at the corresponding ends of said rod and said cylinder, respectively.

11. Assembly according to claim 10 wherein a longitudinally extending elongated element is provided between said cylinder and one of said racks and fixedly secured to the ends of said cylinder, wherein the corresponding fixed length arm means for said one of said racks is connected articulatedly to one corresponding end of said elongated element and the corresponding variable length arm means for said one of said racks is fixedly connected to the opposite corresponding end of said elongated element, and wherein the corresponding arm means for the other Of said racks are connected articulatedly to the corresponding rod ends.

12. Advancing rack assembly for a mining prop arrangement, which comprises a first longitudinal rack and a second longitudinal rack in side by side relation, adapted for supporting thereon mining prop overhead bearing means which alternately extend into and retract from engagement with a mine roof, longitudinally extending coacting moving means including a first moving part and a second moving part disposed between said racks, said parts being operatively interconnected for alternate movement longitudinally with respect to one another yet being secured from transverse and angular movement with respect to each other, a first arm of substantially fixed length interconnecting transversely said first rack with said first part and a second arm of substantially fixed length interconnecting transversely said second rack with said second part, first variable length connecting means spaced longitudinally from said first arm and interconnecting transversely said first rack with said first part and second variable length connecting means spaced longitudinally from said second arm and interconnecting transversely said second rack with said second part, at least one of said first arm and said first variable length connecting means interconnecting articulatedly said first rack with said first part and at least one of said second arm and said second variable length connecting means interconnecting articulatedly said second rack with said second part, and means to vary the length of said connecting means.

13. Assembly according to claim 12 wherein said first and second arms are disposed at opposite longitudinal ends of said racks, and said first and second variable length connecting means in turn are disposed at correspondingly opposite longitudinal ends of said racks.

14. Assembly according to claim 13 wherein said first and second variable length connecting means are articulatedly connected at one end to the corresponding moving part and substantially fixedly connected at the opposite end to the corresponding rack, and said first and second arms are articulatedly connected at one end to the corresponding moving part and substantially fixedly connected at the opposite end to the corresponding rack, wherein said means to vary the length of said variable length connecting means includes a corresponding coacting transverse piston cylinder means extending operatively in the direction of each said variable length connecting means, and wherein each said variable length connecting means includes a pair of telescoping members, one said member being connected substantially fixedly to the corresponding rack and the other said member being connected articulatedly to the corresponding moving part, the transverse piston of said transverse piston cylinder means being connected to one of said telescoping members and the transverse cylinder of said transverse piston cylinder means being connected to the other of said telescoping members, whereby upon coaction of a particular transverse piston cylinder means the length of the corresponding variable length connecting means will vary and in turn the corresponding rack and moving part interconnected thereby will diverge with respect to one another and define an angular position with respect to one another difiering from their previous position with respect to one another, 15. Assembly according to claim 14 wherein said moving means include coacting longitudinal piston cylinder means having a pair of parallel piston rods as said moving parts, each said rod carrying a corresponding double acting piston disc fixedly thereon remote from the ends thereof, and a corresponding pair of parallel double acting cylinders operatively slidably enclosing the correspondmg pistons and each having a corresponding forward head end and a rearward head end slidably mounted on said rods, said cylinders being fixed with respect to one another against longitudinal and transverse displacement and being longitudinally oflset with respect to one another such that the forward head end of one such cylinder is adjacent the rearward head end of the other such cylinder while the rearward head end of said one such cylinder is remote from the forward head end of said other such cylinder, the ends of said rods extending outwardly beyond the corresponding ends of said cylinders, and said racks being interconnected by said arms and said variable length connecting means to the corresponding ends of said rods, respectively.

16. Assembly according to claim 13 wherein said moving means include coacting longitudinal piston cylinder means having as said moving parts a longitudinal piston rod carrying a double acting piston disc fixedly thereon remote from the ends therof and a corresponding double acting longitudinal cylinder operatively slidably enclosing said piston and slidably mounted on said rod, the ends of said rod extending outwardly beyond the corresponding ends of said cylinder, wherein a longitudinally extending elongated element is provided between said cylinder and one of said racks and fixedly secured to the ends of said cylinder, wherein said first arm is articulatedly connected at one end to one end of said rod and substantially fixedly connected at the opposite end to a particular rack and said first variable length connecting means is articulately connected at one end to the opposite end of said rod and substantially fixedly connected at the opposite end to said particular rack, while said second arm is articulatedly connected at one end to one end of said elongated element and substantially fixedly connected at the opposite end to the remaining corresponding rack and said second variable length connecting means is substantially fixedly connected at one end to the opposite end of said elongated element and substantially fixedly connected at the opposite end to said remaining corresponding rack, wherein said means to vary the length of said variable length connecting means includes a corresponding coacting transverse piston cylinder means extending operatively in the direction of each said variable length connecting means, and wherein each said variable length connecting means includes a pair of telescoping members, one said member of each said variable length connecting means being connected substantially fixedly to a corresponding rack with the other said member of one of said variable length connecting means being connected articulatedly to said piston rod and the other said member of the other of said variable length connecting means being connected fixedly to the adjacent end of said elongated element, the transverse piston of said transverse piston cylinder means being connected to one of said telescoping members and the transverse cylinder of said transverse piston cylinder means being connected to the other of said telescoping members, whereby upon coaction of a particular transverse piston cylinder means the length of the corresponding variable length connecting means will vary and in turn the corresponding rack and piston cylinder means moving part interconnected thereby will diverge with respect to one another and define an angular position with respect to one another differing from their previous position with respect to one another.

17. Travelling hydraulic frame device for mining, comprising a pair of prop-supporting racks arranged side by side, arms extending from the ends of each rack toward the arms of the other rack, longitudinally disposed piston rods in side by side relation and mounted articulatedly on said arms, a pair of longitudinal cylinders integrally interconnected and containing said piston rods with the ends of said rods extending beyond the corresponding ends of said cylinders, and hydraulic cylinder and piston means interconnecting operatively certain of said arms with the adjacent rack, the remaining arms being directly connected with said racks, said hydraulic cylinder and piston means being provided to change the etfective length of certain of said arms correspondingly and in turn the angular disposition of the adjacent rack thereto with respect to the other rack.

18. Travelling hydraulic frame device for mining, comprising a pair of prop-supporting racks arranged side by side, each rack having pit prop means supported thereon, arms extending from the ends of each rack toward each other, longitudinally disposed piston rods in side by side relation and mounted articulatedly on said arms, a pair of longitudinal cylinders integrally interconnected and containing said piston rods with the ends of said rods extending beyond the corresponding ends of said cylinders, and hydraulic cylinder and piston means interconnecting operatively certain of said arms with the adjacent rack, the remaining arms being directly connected with said racks, said hydraulic cylinder and piston means being provided to change the efiective length of certain of said arms correspondingly and in turn the angular disposition of the adjacent rack thereto with respect to the other rack.

19. Device according to claim 18 in which said longitudinal cylinders are longitudinally fixedly displaced with respect to each other.

20. Travelling hydraulic frame device for mining, comprising a pair of prop-supporting racks arranged side by side, arms extending from the ends of each rack toward the arms of the other rack, resilient interconnecting element means, a longitudinally disposed piston rod mounted articulatedly on the arms of one of said racks and a longitudinally disposed cylinder mounted via said resilient interconnection element means on the arms of the other of said racks, said longitudinally disposed cylinder being articulatedly mounted via said interconnection element means on one of such arms of said other of said racks and operatively containing said piston rod with the ends of said rod extending beyond the corresponding ends of said longitudinally disposed cylinder, and hydraulic cylinder and piston means interconnecting operatively a given arm between said one rack and said piston rod and another given arm between said other rack and said resilient interconnection element means for said longitudinally disposed cylinder, said longitudinally disposed cylinder being fixedly mounted via said interconnection element means on said another given arm, and said hydraulic cylinder and piston means being provided to change the effective length of the arms interconnected therewith and correspondingly in turn the angular disposition of the adjacent rack thereto With regard to the other rack.

References Cited by the Examiner DAS, German Application, published 3/60, 1,078,068.

CHARLES E. OCONNELL, Primary Examiner.

JACOB SHAPIRO, Examiner. 

1. ADVANCING RACK ASSEMBLY FOR A MINING PROP ARRANGEMENT, WHICH COMPRISES A PAIR OF RACKS ARRANGED IN SIDE BY SIDE RELATION, LONGITUDINALLY OPERATIVE MOVING MEANS INTERPOSED BETWEEN SAID RACKS AND INCLUDING COACTING ELONGATED PORTION MOVABLE LONGITUDINALLY WITH RESPECT TO ONE ANOTHER YET BEING SECURED IN THEIR ENTIRELY FROM TRANSVERSE AND ANGULAR MOVEMENT WITH RESPECT TO ONE ANOTHER, AND CONNECTING MEANS INTERCONNECTING SAID RACKS CORRESPONDINGLY WITH SAID MOVING MEANS VIA CORRESPONDING ELONGATED PORTIONS THEREOF, SAID CONNECTING MEANS INCLUDING VARIABLE LENGTH ARM MEANS FOR ADJUSTING ANGULARLY WITHIN PREDETERMINED ANGULAR LIMITS AT LEAST ONE SAID RACK WITH RESPECT TO THE OTHER AND ALSO INCLUDING LONGITUDINALLY SPACED THEREFROM AT LEAST ONE ARTICULATED CONNECTION IN SAID CONNECTING MEANS BETWEENU A CORRESPONDING ONE OF SAID ELONGATED PORTIONS OF SAID MOVING MEANS AND SAID AT LEAST ONE RACK HAVING SAID AT LEAST ONE VARIABLE LENGTH ARM MEANS, SAID MOVING MEANS THROUGH SAID CONNECTING MEANS OPERATING TO DISPLACE LONGITUDINALLY SAID RACKS WITH RESPECT TO ONE ANOTHER AND IN DEPENDENCE UPON THE LENGTH OF SAID VARIABLE LENGTH ARM MEANS TO DISPLACE ANGULARLY SAID AT LEAST ONE RACK WITH RESPECT TO THE OTHER AS WELL. 